I had this initial problem back in 2000. After a long car ride with the sun in my face most of the day, I began to get a tingling sensation in my lips (I had not been drinking alcohol). That night, my lips and penis were swelled up significantly. After a day or two, water-blisters formed on my lips and penis (they were yellowish). They eventually broke, and turned into red sores on my penis. I also got canker sores in my mouth to the point it was difficult to eat, and cold sores on my lips. I saw a doc about the mouth sores (too embarrassed about the others) and he gave me meds which eventually got rid of the canker sores. This happened to me again a few months later, and has happened probably 3-4 times total since then. All the other times it has occurred, sun exposure and drinking alcohol seem to be the only similar factors. After this exposure, I get a tingling sensation in my lips and my penis itches pretty badly. The second time it happened I saw a doc who saw me at the "swelled" stage and said I had an allergic reaction. He gave me some antihistamine, which reduced the swelling, but I went back to him several days later when the sores had formed and he was shocked at what had happened. He had me do a blood test for herpes, which came back negative (however, this has been some time ago and I don't remember the exact timeline, I believe he also prescribed acyclovir which I've been told can mask herpes in the blood test). After this blood test came back negative I saw an allergist and a dermatologist. The dermatologist diagnosed me with erythema multiforme, but said he couldn't be sure if I had herpes or not until I had another outbreak and he did a culture sample. That has been a couple years ago, and I have been very careful to not drink and be out in the sun without sunscreen and protective lip balm on. I am still not 100% positive I don't have herpes, though the blood test did come back negative (it had also been close to a year since I'd had sex when I had the first "episode," and I was not sure how long the virus takes to pop up after exposure). I've had a few sexual partners since then, and I have been hesitant to bring it up with them since I was told I did not have the virus (don't want to cause undue worry). At the same time, I don't want to be dishonest with future partners.
My question is: does this sound like a simple allergic reaction, does it sound like it's for sure herpes, or erythema multiforme brought on by an allergy, or something else? I have scoured the web for cases like mine and have yet to find them. Other symptoms of an outbreak include swollen glands in the neck, general malaise, and clay-colored, strange-smelling stools.
I'm hoping this is some weird allergy since the sores only happen after I get the swelling. In my research on erythema multiforme, I have learned it usually crops up on the extremeties (hands, etc) which was not the case with me.
Any help/advice would be great!